Pharmacological characterization of CGRP1 receptor subtype in the vascular system of the rat: studies with hCGRP fragments and analogs

Peptides. 1990 Sep-Oct;11(5):885-9. doi: 10.1016/0196-9781(90)90003-n.


In order to examine whether the truncated fragments of hCGRP, hCGRP(8-37) or hCGRP(12-37), behave as competitive CGRP receptor antagonists in the vascular system of the rat, systemic blood pressure was continually monitored in pentobarbital-anesthetized Sprague-Dawley rats. The IV administration of 7.9-527 pmol hCGRP/rat caused dose-related reductions in mean arterial blood pressure that lasted, depending on the dose, about 3-10 min. In contrast, hCGRP fragments 8-37 or 12-37 proved inactive up to 60,000 pmol/rat. Pretreatment with either 10 or 30 nmol hCGRP(8-37) or 20 or 90 nmol hCGRP(12-37)/rat reduced the magnitude of the CGRP-induced hypotensive responses caused by 79 pmol hCGRP/rat; pretreatment with 10 nmol of the hCGRP fragments displaced about 3-fold the hCGRP as well as the [Cys(ACM)2.7]hCGRP dose-response curve to the right in a parallel fashion. The specificity of hCGRP(8-37) as a CGRP receptor antagonist was documented by the finding that it did not antagonize the hypotensive responses induced with bradykinin, histamine or substance P.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Binding, Competitive
  • Blood Pressure / drug effects*
  • Bradykinin / pharmacology
  • Calcitonin Gene-Related Peptide / metabolism*
  • Calcitonin Gene-Related Peptide / pharmacology
  • Dose-Response Relationship, Drug
  • Histamine / pharmacology
  • Humans
  • Peptide Fragments / metabolism
  • Peptide Fragments / pharmacology
  • Rats
  • Rats, Inbred Strains
  • Receptors, Calcitonin
  • Receptors, Cell Surface / classification*
  • Receptors, Cell Surface / drug effects
  • Receptors, Cell Surface / metabolism
  • Substance P / pharmacology


  • Peptide Fragments
  • Receptors, Calcitonin
  • Receptors, Cell Surface
  • calcitonin gene-related peptide (8-37)
  • Substance P
  • Histamine
  • Calcitonin Gene-Related Peptide
  • Bradykinin